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Chapter 64 Configuring WCCP Version 2 Services About WCCP
Understanding WCCP Configuration
Multiple routers can use WCCP to service a cache cluster. Figure 64-1 illustrates a sample configuration
using multiple routers.
Figure 64-1 Cisco Content Engine Network Configuration Using WCCP
The subset of content engines within a cluster and routers connected to the cluster that are running the
same service is known as a service group. Available services include TCP and User Datagram Protocol
(UDP) redirection.
WCCP requires that each content engine be aware of all the routers in the service group. To specify the
addresses of all the routers in a service group, you must choose one of the following methods:
Unicast—A list of IP addresses for each of the routers in the group is configured on each content
engine. In this case the address of each router in the group must be explicitly specified for each
content engine during configuration.
Multicast—A single multicast address is configured on each content engine. In the multicast address
method, the content engine sends a single-address notification that provides coverage for all routers
in the service group. For example, a content engine could indicate that packets should be sent to a
multicast address of 224.0.0.100, which would send a multicast packet to all routers in the service
group configured for group listening using WCCP (see the ip wccp group-listen interface
configuration command for details).
The multicast option is easier to configure because you need only specify a single IP address on each
content engine. This option also enables you to add and remove routers from a service group dynamically
without needing to reconfigure the content engines with a different list of addresses each time.
The following sequence of events describe how WCCP works:
1. Each WCCP client (content engine) is configured with a list of WCCP servers (routers).
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